When patients are being mechanically ventilated on an intensive-care ward, for example, the patient to be ventilated is connected pneumatically to the ventilator or respirator by a system of ventilation tubing. Because the breathing gas supplied to the patient must be adjusted with respect to temperature and humidity to meet the physiological needs of the patient, a respiratory humidifier is arranged in the inhalation or inspiration tube to heat and humidify the breathing gas. The respiratory humidifier comprises a liquid container filled with distilled water, through which the breathing air is conducted and humidified.
To prevent moisture from condensing inside the system of ventilation tubing, the inhalation tube and expiration or exhalation tube are usually provided with electrical tube heaters to heat the flowing inhalation or exhalation gas during operation. Loops of heating wire, for example, are used, which are integrated into the inhalation and exhalation tubes, or the inhalation and exhalation tubes are wrapped with coils of heating wire.
The breathing air temperature is usually regulated by means of a temperature sensor arranged near the patient; the sensor is connected by means of an electrical measurement line to a control unit, which is installed in the respiratory humidifier, for example. It is therefore logical to design the electrical contact elements of the electrical lines on the tube connectors jointly with the pneumatic connection elements in order to minimize the number of separate connections.
Pneumatic tube couplers with electrical contact elements integrated into them are described in, for example, EP 1 127 583 A2; DE 199 58 296 C1; DE 197 25 875 A1; and US 2003/0059213 A1. A system which connects the two functional components of the inhalation tube to the respiratory humidifier is known from EP 1 369 141 A1. The connection element or tube coupler comprises a male plug section on the liquid container of the respiratory humidifier, onto which a female sleeve section at the end of the inhalation tube can be placed. Electrical contact elements are arranged laterally on the sleeve section of the inhalation tube; when the sleeve section is placed on the plug section, these elements are brought into contact with another electrical contact on the housing of the respiratory humidifier to establish the electrical connection.
The disadvantage of the tube connecting system described in EP 1 369 141 A1 is that it can be placed onto the respiratory humidifier in only one direction, namely, from above. Before the connection is made, the electrical contact elements on the housing project awkwardly from the housing as independent elements and thus interfere with the appearance and practicality of the respiratory humidifier. Another disadvantage arising from this connecting system is that it limits the scope of possibilities for designing the respiratory humidifier. Logical improvements in this regard are therefore almost impossible to make with the existing devices.
It is therefore the object of the present invention to provide a connecting system for connecting a ventilation tube to a respiratory humidifier, which system offers a variety of ways in which the electrical contact elements can be connected to each other and which thus makes it possible to improve the design and appearance of the respiratory humidifier. It is also an object of this invention to provide a convenient kit including the liquid container and the tubing having such advantages.